Lignin-based highly sensitive flexible pressure sensor for wearable electronics

The development of flexible sensors with low cost, facile preparation and good reproducibility is of profound significance for wearable electronics and intelligent systems. Lignin is an aromatic composition of lignocellulosic biomass and known as a cheap, renewable, and environmentally friendly resource available everywhere. In this study, we present a simple and low-cost approach for the preparation of a highly electrically sensitive and flexible composite with polydimethylsiloxane and carbonized lignin via a facile process (CL/PDMS). This electrically sensitive flexible composite can be used in the preparation of a piezo-resistive sensor, which exhibits stable and fast response to loading and unloading stress in 60 ms and 40 ms, respectively. The sensor prototype displayed high sensitivity (57 kPa(-1)), wide range of working pressure (from 0 to 130 kPa) and excellent durability. The signals of pulse rates and the force needed for picking up items were successfully collected with this CL/PDMS sensor prototype. With the simple process for fabrication, low-cost of the filling material and excellent performance, we believe that the lignin-based sensitive flexible composite CL/PDMS is promising for applications in wearable electronics and intelligent systems such as health monitoring, smart skins, sports and other related areas.